Given how much got accomplished with prior models of the atom, I wouldn't say these are necessarily good examples of passwords. They also weren't approximations so much as older models. It's sort of like learning the geocentric model first, and then later updating to the heliocentric model, and then finally learning that the sun actually revolves around the center of the universe as well.

I'm honestly a bit puzzled as to why we insist on teaching so many older models in science, without appropriately labeling them. Perhaps the math is easier to learn, and perhaps it's just much easier to teach the models you grew up with originally.

Actually, when I learned these I learned them all at once, with the "older model" tag attached to them, and then I was given a "current model" that I was told that I wouldn't understand yet, and so we worked with the planetary system thing.